Grenade gun



Feb. 13, 1923. A. G. BERGMAN GRENADE GUN 2 sheefs-sheet 1 Filed June 8, 1916 NVENTOii $4 ya By Attorneys,

Feb. 13, 1923.

A. G. BERGMAN GRENADE quu Filed June 8, 1916 2 sheets-sheet 2 INVENTOR d WITNESSES WW rneys,

Patented Feb. 13, 1923.

AXEL G. BERGMAN, OF NEIV YORK, N. Y AS SIGNOR TO ELMER ORDINANCE CORPORA- TIOhT, OF EAST ORANGE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

eanmmn eon.

Application filed am 8,

To all whom it may concern:

Be it known that I, AXEL G. BERGMAN, a subject of the King of Sweden, residing in borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Grenade Guns, of which the following is a specification. 7

This invention relates to trench guns, and aims to provide certain improvements therein.

In my Patent No. 1,317319, dated September 30, 1919, I have described and claimed a trench gun intended primarily for throwing bombs, grenades, or other similar devices in which a substantially constant propelling charge is used, and the angle of the gun is preferably fixed, the range being,

- altered by varying the size of the explosive chamber at the rear of the projectile. In the specific construction shown theexplosive chamber is varied in capacity. by altering the point at which the projectile is held in the barrel of the gun at the time of explo- S1011.

The present invention aims to provide a more accurate and effective weapon of this typ 1 It is highly desirable that the explosive charge used in this type of gun shall be composed of smokeless powder, since this explosive not only gives the best results in practice, but also conforms to usual service conditions. It is also desirable that the explosive shall be contained in a cartridge case of some standard caliber, and that the car.-

tridge shall conform as nearly to ordinary service cartridges as possible. For this purpose I have employed service ammunition from which the balls or bullets have been removed, or, in other words, what may be said to be blank cartridges.

In experimentation, however, I have found that such cartridgesare subject to several disadvantages. A. thorough ignition of the smokeless charge cannot take place in the ordinary blank cartridge'because of the fact that smokeless powder requires a very considerable back-pressure to properly ignite it. This back-pressure in the ordinary ball'cartridge is supplied by the bullet itself which 1916. Serial No. 102,494.

is crimped into the cartridge case and which 1s retarded to a great extent 1n its passage through the ordinary gun'by the rifiing of tion. The effect of this in a trench gun,

particularly of the type where the explosive chamber is varied insi'le, is that'the explosive chargenot only does not reach anywhere near its maXimumefiicienc-y, but also is uncertain in its operation, with the re sult that that nice degree of accuracy in the range which is so desirable is not attained.

Oneof the principal features of my invention is the provlslonof a means, par ticularly '1n connectlon with a gun of thls type, for building up a pressure which will insure a definite or standard. explosive-effect,

which is preferably the maximum which a given charge of smokeless powder will produc'e.

The lnvention also includes, certain fea tures of the gun itself withwhich the cartridge is to be combined in practice, which features of construction will be hereinafter more fully described. Referring .to, the drawings which illustrate one form of the invention,- Fig. 1 is a side clevati.on,- partly in section of the gun.

Fig. 2 is aplan of the breech and rear of the gun.

Fig. 3 is a hOI'lZOlltttl section, showing the firing hammer in cocked condition.

Fig. 4: is a vertical section, showing the hammer in firing position.

I v u lug. 5 1s a rear elevation of the breech, certain parts belng shown 1n section.

Fig. 6 is. an elevation, partly in section' I of the preferred form'of cartridge.

Referring first to Figs. 1 to 6, let A indicatethe gun as a whole which is best provided with a split sleeve B clamped to the barrel by suitable bolts. The. sleeve has a pivot C at its under side which is held in a recess formed in a head'D being removably retained therein by 'a' bolt or thumbscrew E. The head D is formed or provided with lugs F, .which constitute pivots for the rear legs G G which are provided other to secures firm foundation for the gun i The gun is capable of elevation and depressionto a certain degree through its'pivotal connection with the trame means being. provided lei/accurate adjustment and for holdingv it in its adjusted positions. Across the rear legs G G is fixed a bar J through the middle portion of: which is tapped a thumb-screw K, the inner end of which is adaptedto a plate L screwed. to the under side the barrel as shown in Figure l; The eppioximate elevation having been obtained by adjustn'ient of the frame, the thumb-nut manipulated until the precise degree oi? elevation is attained.

prefer to provides spirit level. l\l. or other means for ascertainingr the horizontal and in the '(OIlShlUClilOll shown'the level M pivoted-to an arm N carried on the sleeve B, a thumb-screw being provided for adjusting it in its horizontal position. A graduated sector 0 is shown as fixed to the barrel, the graduations indicating the degree of vari-' ance fromthe horizontal. f I

If it is desiredto adjust the gun as to horizontal direction, the latter be swung around the pivot (land the thumb-screw K will engage the plate L at varying parts of its length, while at the same time serving as ameans for vertical angular adjustment,

It is preferred toprovide the plate with flanges P P in order to limit the horizontal adjustment by engagement with the end of the screwli. I

lVhile'IneZlns arev provided "for minor V61- tical adjustments. for, range, the principal means for varying! the range the position mg of the projectile atsuchpoints in the barrel as will allow of a smaller or greater explosion chamber behind it. Inv Fig. 1 of the drawing the projectile Q, is shown as held about midway inthe barrel; the explosion chamber comprising principally that part of the barrel which lies between the projectilev and the breech. In order to accurately adjust the position of thehprojectile I providean adjusting rod S which extends longitudinally of the gunand passes through the breech. as best shown in Figs. 1 2111619. In order to secure a scale and guide for the adjusting rod S, I provide two guide rods end hl which are "screwed into the breech and fixed thereto means nuts V W.

Moving on the rods T and U is aslide yoke X tothe .middle of which the lower end of adjustinmrod S is fixed. One ofthe guide rods (s own as U) is provided with a graduated scale indicating the position of the adjusting rod, and consequently the position of the projectile in the barrel. In order to fix the adjusting rod firmly in its adjusted positions, I provide atthumb-nut A which screws through the plate L and either engages the rod S directly, or preferably through the medium of a key .or clamping-plate B held loosely above the plate L, which when pressed against the rod secures a greater frictional surface than would the end of the thumb-screw AT alone. Thecartridge is preferably contained in a cartridge chamber C formed in the breech I) which chamber may be of ordinary proportions, or may be modified, as hereinafter pointed out.

horizontally on. a .'vertical pivot F; In the drawings the breech hloclc is slunvlrclosed and locked by locking lever V- pivoted to swing-"vertically around a horizontal pivot H, as best seen in Fig. 3. v Fixed to the breech is a: locking lug I in front of which the locking lever G swings, a'ndby means of which the breech block is held its closed position against back pressure. during firing. i i

The v hammer J which is pivoted on the pivot F, and which is adapted to strike the firing pin L contained in a recess in the breech block, as best seen in Fig. The firing pin is firing mechanism shown comprisesa i lOO held retracted by aspring Min the usual 'lWhen the trigger is released the hammer is impelled forwardly by a spring Q," acting through a linlr'R connected to a pin on the hammer, asbest shown inFig. 3.

In order'to prev'ent any possibility of firinc: unless the breech block is closed. and locked, the pivot H" is' fixed by a pinl'i to the locking lever G; so that'lthe pivot oscillates when the lever is manipulated. At the outer end of the'pivot isfiXed a cam sector S which, when. the breech isclosed and locked, as shown in Fig. 3, is of insufiicient thickness to. prevent the hammer J'] from impacting against the firing; pin. other position, however the thickened edge ofthe cam is interposed between the hammer 1 and the pin. i j I The result of this construction is that afteraea-ch firing operation the locking lever G is tiltedto unlock the breech wherea upon. thebreech block may be swung Back- In any advantages ofb-lack powder has not been foundto'be satisfactory due to the fact that with t-he ordinmy blank cartridgefthere is (nothing-to build up'thepressure'iwithinthe trigger luntil the-qlugjP" of the hammer passesthe :nose U and becomes engaged therewith. i'i henthe breech is 'a'gainclosed, the hammer'ls retained 1n-1t-s COC-lCGCl'POSliElOIl 1 .shownin Fig.3.

cartridge case. which'is best seenin FigsfQ and 4. It comprisesa curved member V pivoted tothe breechv block and-having a nose XV adapted to slip over the cartridge rim on the inward movement of the. breech block. For this purpose the extractor V 7 pivoted -looselyat X as shown, so that opened the nose W pulls the cartridge case out. of the cart-ridge'chamber and n-s o (10-.

it may tilt sufficiently to pass over the rim.-

spring Y tends to hold it in its'downward position. As the breech block is .ing it swings around its; pivot sufliciently to outof its chamber. I

produce a more oruless-straight.pull-on the As before statedi in' a gun'of this type accuracy of range is secured principally by fth'e barrel is rapidly fouled and requires.

variation of I the f explosion chamber behind It is essential to, successful firing, however, that the explosive force of I the cartridge shall lee-uniform; otherwise a the" projectile.

variable'factor '.is introduced which intervferes fw ith accuracy of firinggi Ordinary jblilck powderisnot; suitable for the exploe sive-charge in'the cartridge fora number or reasons principally due to the fact that too frequentswabbing. (On the otherhand,

smokeless powder while avoiding the discartridge to a; point'where thorough combus- H tion of the cartridge charge is secured. One of. the principal-features of thepresent invention is hence the provision of means whereby a uniform explosive force is obtained with a given charge. Preferably this force is the maximum which the 'quam tity ofjcharge willafford. I I

arious methods f -The invention"; includes v ,ofQaccom lishing this-"result, but the-simplest is in the construction of the cartridge itself; 'In Fig. '61 have illustrated the prebe of any usual'construction. I have'indirated-a charge- 0f smokeless powder 13 which chargemaybe-varied but which bestferred form. The cartridge casing A 'may a 1 conformsto service conditions. "The invenpressure, which is preferably, theminimum ffsufiic e t*disshe 'tQ..P T 1 i -f i e removal of the cartridge. ,T he result of this I movement' is thatthe inner face j-T hammer moves aroundjthenose' U of the he c'artridge casing is bent the length of'timewhich is required for this i i 1 j" 5 tridge casingwill determine the pressure 1 I p V -w-hichis necessaryto disrupt the flangeand U I prefe1 to provide an extractor for the.

purpose- They ishould -be so proportioned 1 that they jwillinot disrupt until about the minimum] pressure required is reached. In theordinary service; cartridge casing, howevn-wherefthe gauge of metal is small I plug F 2 into the cartridge casing which best lies immediatelytback of the disk G and' I i se have found it very efi'ective' to introduce a vides sufficient back pressure for thorough ignition, but also produces. a great imiromt,

ity in explosive effect, so that With..-care in,

loading a succession of t'zartridges will; fire;-

the projectileis greatly increased; Practically," themeans for introducing'the back p'ressure*: should be suchthat when forced out-ref the'c-artridge they will not plerce the projectile, and thereby cause, ex-

plosion, of-ihe .proj'ectileiin the barrel, or

i a'succession of projectileswith-great accu-i I racy, and where the maximum explosive force s-prov ded .forythe posslble rangeof in diameter v is in ,ekcessfo'f that of thecar-i tridge. This introduces a condition which v a,. -quiltedbeing obtained by driving a bullet rifiing asin the case of ordinary does not permit of. the back-pressurere-T along the guns. v I The building-up of the pressure requj ed may be obtained inother ways thanby the construction showng asfor'instance by con structin; the diameter ofthe exittgpassageg G? of-the cartridge-chamber as ume in- Fig; 4 to a point-where the gases escapewith difficulty. Orthe exit passage G maybe. 5 i so m d s n e *p Q ias G 7 or, F?) of the cartridge" in such manner. as '3'} toretardthe passage ofg'the latter into theexplosion'ch'amber; Other.waysfof produc i While have] h wn an described I cii cform iofthe inventiomitwill be understood;

ing the result will suggest themselves.

that l. dofirot wishito'be limited thereto,

since various changesrmay be made therein without depart ng from the spirit, of the 'inv'ention."

l-claimis'z hf 1. Ina, trench gum-thecombination ofa breech, a barrel-secured thereto; an adjusts ing "rod passing through said breech into by Sam pf d adgustilg ma; ran rme i holdmg lidladluSfi ngd" F YY P 2,111 gtrench" un',g.they 9 mat 

